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Dec 2016
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Dec 2016
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Enza3D
Dec '16

If the issue is with the part design, then it is the fault of the customer if the final print does not work as expected. Tolerancing is a core tenet of mechanical design; if you brought a poorly designed part to any prototyping shop, it’s on you if things don’t work once manufacturing is done. If a print is within the allowable accuracy range (1 mm or 1%) then it’s not the Hubs fault.

Shapeways and any other larger print shop is very much what you see is what you get; as long as they deem a part printable, they will print it but that’s it. If it was printed how it was supposed to, they do not care if the design itself was incorrect.

PepCo_Parker
Dec '16

Yes but let’s say two parts were designed to fit each other, but we’re designed improper via a hole or gap being a mm too small or too large. Diagnosing these issues before printing is nearly impossible, and the customer could argue they don’t fit due to tolerances of the hub being poor. Both of these sides of argument are hard to prove unless you are there in person. With the way 3D hubs handles refunds I could forsee it being an issue

PlastiPrint3D
Dec '16

Unfortunately yes. The managerial speak trying to make it sound like it will benefit me as a hub and big warning across the top of my dashboard saying it’s happening tells you all you need to know.

It’s getting towards the point where I’m considering if I want to be associated with 3Dhubs as the requirements are starting to pile up for the little cash you get back from the job.

cobnut
Dec '16

Well, as far as dimensions are concerned, any decent slicing program will report the printing dimensions of the sliced model, so there’s no need to guess. In terms of getting the prints right (accurate to those dimensions) why shouldn’t they be? I know all my prints come out well within the tolerances suggested by 3DHubs so I don’t see the concern. I always check with a customer what the purpose of their print is anyway, and if I now have to remember to also specifically ask about tolerances, that’s really no big deal - heck, we could all easily put together a stock “first question” to cut and paste for any print order that covers things like this.

To be honest, I’m not seeing a problem here. If I were a customer, not a Hub, I’d expect there to be controls like this and I’d expect the printer to deliver me high quality prints that match the model I’ve uploaded. If my model is unprintable, or I want a dimensional accuracy that’s unrealistic, then that’s another matter, but the tolerances being suggested here seem very reasonable and totally what I’d expect from a paid service.

Sorry if this isn’t a popular view, but I can’t see the problem with wanting to produce high quality prints that match the customers’ requirements. Have I missed something here? Do the majority of Hubs often print models with inaccurate dimensions? Does no one else discuss the print with their customer to get an understanding of the job and any specific challenges?

Enza3D
Dec '16

@cobnut The issue with using STL models for dimensioning is that they are dimensionless; what we get in a slicer is just the software’s representation of hundreds or thousands of triangles. Because of this curves become faceted, so if a customer has a small hole and they did not export it properly, they could easily end up with a hexagon instead of a circular hole. It’s just infinitely easier and more accurate to work from a parametric model than an STL file. It’s just poor practice in industry to dimension from STL files. To be clear, I do not have an issue with the set dimensional accuracy range or my ability to meet it. I have an issue with the complete lack of discussion as to how it’s going to be policed (sorry, but a picture won’t cut it) and the space for misinterpretation on the customers side as to what that means. I have already had to deal with customers giving me the wrong file and wanting a refund because it was “printed wrong” but the model was fundamentally wrong to begin with.

PepCo_Parker
Dec '16

My concern isn’t hitting the targets, it’s people manipulating the system in their favour to receive free parts. Stl files Do Not show dimensions. Only overall. This will not show dimensions of inner details and walls. These new standards make it easy for someone to set a pair of calipers improperly and fight for a refund. Meeting the requirements is not at all the issue and I urge you to please read what we have discussed in the past.

PepCo_Parker
Dec '16

As well if you had read my post, I expressed that I felt a large part of 3D hubs is just mutual trust and proper communication. I explained that my practice has always been to discuss with the customer what is needed for the part and if tolerances are needed. So my question is why does 3D hubs have to get involved now? I saw no issue with the system before. Really feels like they are simply creating problems to fix.

Perry_1
Dec '16

@PlastiPrint3D So I do not see this warning. Can you cut and paste it here?

@Robin

So far, I am uncomfortable with the wording that has been provided. Perhaps we could give some input on that before it goes live!

John3d
Dec '16

remember with out our printers 3d hubs would be nothing you have a voice there is no benefit that i can see for a hub with the new rules apart from more work for us.

PepCo_Parker
Dec '16

Maybe instead of enforcing these rules the way they are, they should have provided tools to educate hubs on better ways to quote and accept an order, such as good questions to ask and topics to touch on when explaining. If people not getting the tolerances was an issue, this was not the way to go about it. Unfortunately it doesn’t seem 3D hubs really cares for our opinions on that, the distinct lack of response from any of their employees is only even more evident of that.

PepCo_Parker
Dec '16

Unfortunately with the amount of Grant money 3D hubs has received recently, our opinions really don’t mean anything. I’ve seen this time and time again where as soon as big figured come into play management goes to shit. Very disappointing. This whole thing is really pushing to go off 3D hubs for business, which was not something I wanted to do. A year ago, all I did was promote 3D hubs as I liked what it was about, and how their aim was to educate people on additive manufacturing. I can’t help but think they’ve lost their ways since then.

rkelly
Dec '16

To further this point, 95% of hubs and 99% of customers do not have sufficient metrology to measure the things that are being printed. Bounding box dimensions are a great tool to get the relative size of a part in a digital space but are useless in the real world. Most prints are not rectilinear and are impossible to measure short of scanning them back into the digital space and comparing them to their source file. Taking a photograph of a print next to a ruler or with a caliper are both useless verification methods unless focal length of camera and a bunch of other easily manipulated factors are taken into account. To validate a dimension the measuring technique has to be objective.

How about instead of holding hubs to a ridiculous standard of quality which are unenforceable and will undoubtedly increase the cost of every FDM print and reduce overall ease of use for this whole system we add a step to the verification process where the hubs have to verify the dimensional consistency of their machine. Hubs could print several calibration cubes and either send them direct to 3D Hubs headquarters or measure them, similar to the initial marvin. This could even be a periodic check. This would be like a drivers license, you need to prove you can do it once or twice and then you’re left alone. Asking for every single print to be measured increases the cost and significantly reduces the appeal of 3d hubs in general for both the customers and the hubs. I truly understand the spirit of what it is you guys are trying to do but implementing blanket rules that cant be enforced without tons of effort not the way to do it.

rkelly
Dec '16

I think its mainly because they dont have enough feedback internally on the practicality and implementation of things they propose. This very much feels like a marketing driven company with very little engineering or maker feedback, which quickly turns into a circle jerk of corporate values and quarterly earnings oriented business moves. The customers needs will slowly get belittled until they are forgotten, all the customers will feel alienated. A new startup will pop up and cater aggressively to the core user needs and 3D hubs will fail as a business. Unless they start listening and discussing the issues at hand with us.

Georgei
Dec '16

Hi Chris,

I understand your concerns as a final user, however wouldn’t be more easy for you and the hubs that print your cabinets to have a list with the specifications that you want your cabinets to be printed (i.e. I want them with so much infill and so much thick walls)?

That way both you and the hub will know what you want? To blame each hub that they haven’t print your part the way that you want when you didn’t gave them any specifications is a little unfair. And no 3DHUBS they should not make standard the specifications that you want your part to be printed because it is not standard for millions of other parts. So my suggestion is to submit your specifications when you place the order.

MadBuggyofDoom
Dec '16

Hi all, newbie here, been lurking as I’ve got a cheap CTC machine I’ve had for a week and been playing with/upgrading, anyway, couldn’t resist weighing in on this one - I used to run a CNC mill for prototyping parts, and there’s no way in hell I’d agree to a 1% tolerance on most small plastic parts, especially ones made hot on the machine, even though I could hold far closer tolerances than that on the machine, why?
Well not only do you have shrinkage to deal with, but if the part relaxes over a few days whilst in shipping, absorbs some moisture whilst it’s sat in their workshop for a week, or you live in a place much colder/hotter than the customer, the plastic parts could have moved out of tolerance just through natural growth/reshaping. You could have a 1% change in dimensions just through normal room temperature water absorption rates alone on such as Nylon going from dry printed back to it’s more normal 2-6%

If you’re going to specify a 1% tolerance you really need to spec out whether that is relative or absolute, and at what temperature and humidity, and explain to the customers that their parts are going need to sit in a room with a controlled temperature and moisture level for a couple of days to stabilise so you can measure them accurately. Otherwise you’re going to have some real issues guaranteeing those tolerances on FF production parts which have all manner of internal stresses just from the way they’re formed, not to mention varying crystallinity not just from surface to interior but also on the filament skin to core. That’s not even taking into account any creep that might occur on the part later on depending on how and where it’s stored.

Enza3D
Dec '16

Thank you for articulating this so clearly, much better than I could have!

PepCo_Parker
Dec '16

Agreed. This brings up great points I hadn’t even thought about. It’s a shame it seems like it will just be ignored by the developers, I hope I’m not the only one who was even more upset to see that email rolled out completely ignoring our questions and concerns. Still a real lack of response on 3D hubs part.

Perry_1
Dec '16

It is really bad form to request feedback on a guidelines, then release the guidelines while still in discussion. It certainly sends a signal that 3dhubs is not listening. Especially when there are really a shortage of replies from 3dhubs for the things being discussed. It implies you asked for feedback to make the hubs FEEL like they have some input, but don’t really have input. With so many of your customers discussing it, and 3dhubs just implementing it during that discussion, it surely seems like you are not listening to your customers. I would like to remind 3dhubs that their customers are the 3d printers, NOT the folks that order the prints. Those are OUR customers. Many that we bring to 3dhubs on our own. Many of OUR customers ask us to work around 3dhubs, but I always push them TO 3dhubs, because the interface, software, and my payment protections are all worth the fee. But make no mistake, I am the 3dhubs customer, not MY customer, who ultimately gets the print.

Serious mistake here in handling your customers, asking for input while implementing the guidelines during the input phase.

I asked what the purpose of the new guideline are, and what problem they are trying to solve. This is key to me liking or not liking the guidelines.
I think the wording is still bad.
Several folks have asked for specific responses from 3dhubs in this discussion, and have not received it.
Folks are interested in how they handle ABS and Nylon prints, that can easily change size by over 1% due to shrinkage or humidity.
Several people asked how the guidelines might be enforced, and how the measuring could be verified.
Some folks stated they felt that they were not being listened to, and this was reinforced by a lack of response by 3dhubs to them.

All in all, I am for the new policy, but this is truly bad form, and a serious mishandling of the situation here by 3dhubs and their customers, in my humble opinion. I am all about increasing the quality of the 3d printing that is going on out there. I have customers who have brought me prints from other hubs, and I am shocked at some of the quality of the prints. So I am all for some better rules. That is not what I am talking about in this post.

It is hard for me to understand how during an ongoing discussion, 3dhubs could just go ahead and implement.

Enza3D
Dec '16

I think you and @Vienna3DPrint have hit the nail on the head. 3D Hubs has forgotten it’s role in all of this. The reality is my customers will come and go with me, especially if I discount 12.5% from my prices if they place orders outside of Hubs. Like you, I try to keep all my orders through 3D Hubs, with the very small exception of those who need to pay by other means (which is common with younger students). Hubs is supposed to be what Etsy is to their shops; Etsy just provides a site and a gateway, the shops do all the rest. Etsy does not own the customers, the shops do, and if the shops leave, so do the customers. It is very much the same here, but 3D Hubs seems to have forgotten that, or doesn’t care anymore because they got their funding.

Either way, the entire handling of this situation has left a very bad taste in my mouth, and I am very displeased to say the least.

PepCo_Parker
Dec '16

From what I’m reading here, it only strengthens my opinion on this as I see I’m not the only one operating this way. I too have requested to do deals outside 3D hubs but I push people to use it for its interface and organization. The way you guys put it is exact. The hubs are 3D hub’s customers, not the people buying parts! Unless they want to hire their own massive sales department to replace all us hubs I suggest they start listening. Until now I’ve not had reason to look into other platforms, and I’ve promoted 3D hubs a lot. This may incline me to look elsewhere to do business.

Vienna3DPrint
Dec '16

Hi

Well, that´s all a good intention, but poor execution. Why ? Because since now I was on the lower end of the price range. I could do that, because I have a full time job (that provides me and my family) and offer my 3D print services in my spare time. Therefore I asked my customers if they want to remove the support material themselves (to get the prints faster) or if I should do it (and they would have to wait a little longer). Often I didn´t even charge the support material for smaller prints. Only for bigger objects with a lot of support and time taken to remove it, I charged a small additional amount. You could say, the time spent for it was for free. Because average EU/US hourly rates for labour would be like twice to five times of the value of the print (guessed…)

It was good that the people could choose, because often they wanted (or had) to improve the print by sanding, painting or other methods. Now this choice is gone. And due to the nature of the producing machine (desktop home use) and method (FDM is the least accurate!) it will cause only disputes printing with non-dissolve-able support material. That makes it about impossible to use a single print head machine.

On the one hand it would be the logical next step for me to upgrade to a dual head machine. On the other hand it will make 3D prints MUCH more expensive for 3D hubs customers. Water dissolve-able support material costs 3-4 times of PLA filament. The dissolving takes about 12-24 hours (if I am correct). Higher and high priced hubs may print already that way and will keep their high price. But the possibility for cheap and fast prints (with customer removing the support) is gone with the change of guide lines.

That is NOT supporting the spread of 3D printing.

I don´t even want to speak about tolerances. It´s quite the same as with 2D prints. What kind of quality can you expect from a €/$ 50,- Printer ? People are then disappointed. Prints are not seamless, have wrong colors, are washed-out, a.s.o. You still have to invest at least 10-20 times more for a decent quality.

So, how can you expect extraordinary results from a €/$ 800,- 3D Printer ? (This average price is a guess. You might have better statistics).

A really awesome FDM print needs a CAD model that considers the abilities of the used 3D printer. It has to consider physical laws. The 3D printer has to be set up in terms of even and balanced print bed, correct space between needle and bed for the chosen resolution, prepared (sticky) print bed, correct temperature for the used filament. The slicer have to be tuned for optimal feed, speed, calculation of the g-code. The filament have to be of good quality. Maybe stored in costly ways (vacuumed). The print environment can have a big impact on the printed results (temperature control, humidity). And maybe more I haven´t considered here and now.

It makes the impression that DIY tools should reach top-professional high end industrial standards.

I don´t want to say that the aim doesn´t impress me, but now the vision has to meet reality.

It is not possible, for a reasonable price, to fulfill the announced standards. If you want the requirements to be met (seriously), then the hub must charge hours of pre processing with a lot of information transfer. Maybe some information is not even available because the customer has also only the stl file. Very often the stl is not water tight. So you need additional tools to repair it. Then, to finally meet the tolerance, a couple of prints (which blocks the machine naturally) to maybe recognise that the tolerance CAN NOT be met. And you can only tell after the support material is removed.

All that costs the hub time and money.

A small 10x10x10cm object could cost likely more then €/$ 250,- if requirements must be met.

This results in three bad things: High prices for FDM 3D prints. Less orders and revenue for hubs. Less profit for 3D hubs.

I would strongly suggest to not activate the guidelines for FDM by Jan. 5th, 2017. Rethink the role of 3D Hubs as a broker between clients and maker.

Refine the platform to be able to choose between instances of print quality. Collect and present possible print outcomes for customers. Not for hubs; they know them just too well.

Thank you and happy new year.

cobnut
Dec '16

@PepCo_Parker :slight_smile:

I’ve actually got an interesting example of the dimension problem right now. The part has a shaft running through the middle and the part itself needs to fit tightly inside a tube, so both the inner and outer dimensions of the cylinder need to be spot on. The client has provided dimensions, but I’ve included what happened on printing (see attached).

Some of the dimensions are OK - the flange at 0.07mm too high is irrelevant for this model for example. The major issue is with the internal diameter that should be 15mm and prints at 14.4mm. I’ve corrected this in the model and it now looks OK, but what’s important here is that all of these dimensions of the printed part are within the 1%/1mm guidelines, even though as printed first time the print was effectively useless. (note, I know some of the dims don’t add up, I’ll put that down to variations in printing thickness and/or lack of coffee).

@Robin3D how should we deal with prints like this? Should we charge more for dimensional accuracy beyond the guidelines, how do we charge for modelling, measuring, testing, etc.?

dims2.png
dims2.png840×435 5.75 KB

Vienna3DPrint
Dec '16

Please just place somewhere in the guidelines: All services are based on best effort by the printing hubs.

That will not put an end to complains, but release the pressure from hubs and puts everybody on the safe side.

Thank you